Multiplier correction mechanism



Sept 9, 1947 c. M. FRlDEN ETAL 2,427,271

MULTIPLIER CORRECTION, lMECHANISM INVENTORS CIEL M FE/DEN ANTHONYMJC/QO BY' i ,Qta

ATTORNEY Sept. 9, 1947. l c. M. FRIDEN ETAL MULTIPLIER CORRECT-IDN MECHANISM Filed Oct. 27, 1941 M wm mmm. u A Y m Q a mmm W nn M2M u A y t I Sept 9, 1947. c. M. FRIDEN ETAL MULTIPLIER CORRECTION MECHNISM Filed Oct'. 27, 1941 5 Sheets-Sheet r3 I l M ZK l Sept. 9, 1947. c. M.` FRIDEN ETAL l MULTIPLIER CORRECTION MECHAN'ISM Filed Oct. 2'7, 1941 5 Sheets-Sheet 5 INVENTORS CARL M. FE/DE'N H/VT/-l/VY MHC/VADO. BY

ATTORNEY Patented Sept. 9, 1947 MULTIPLIER CORRECTION MECHANISM Carl M. Friden, Pleasanton, and Anthony B. Machado, Oakland, Calif., assignors to Friden Calculating Machine Co., Ina,` a corporation of California Application October 27, 1941, Serial No. 416,662

6 Claims.

This application relates to calculating machines I and is concerned more particularly with mechanism for performing plural order multiplication operations.

It is an object of the invention to provide an improved calculating machine ofthe character referred to in which the multiplier selection mechanism can be restored to zero in an advantageous manner.

Anotherr object of the invention is to provide an improved calculating machine wherein the normalizing of the machine due to an erroneous set-up for plural order multiplifying operations can be effected expeditiously.

@ther objects and advantages of the invention will be apparentkfrom the following description of a preferred embodiment thereof, as illustrated in the accompanying drawings, in which:

Figure l is a plan view of a calculating machine embodying. the invention;

Figure 2 is a longitudinal sectional elevation through the machine taken in planes indicated by the line 2 2 in Figure 1 with the carriage removed;

Figure 3 is a fragmentary sectional view through the carriage, the view being vtaken as indicated by the line 3-3 in Figure 1'. The view is complementary to Figure 2;

Figure 4 is a sectional elevational view through a part of the. multiplier mechanism, the View being taken as indicated by the line 4-4 in Figure l;

Figure 5 is a fragmentary detailed view illustrating a portion of the resetting or correction means for the multiplier selection mechanism;

Figure 6 is a sectional elevational view illustra-ting a portion of thedrive mechanism, the view being taken as indicated by the line 6-5 in Figure 1;

Figure 7- is a fragmentary elevational view of a portion of the multiplier control mechanism;

Fig-ure 8 is a sectional plan View of a portion of the multiplier mechanism, the view being taken as indicated by the line 8--8 in Figure 4.

General description The invention is described in apreferred form as adapted to a Thomas type calculating machine, as shown for example in the patents to Friden Number 2,229,889, dated January 28, 1941*;

2,294,683, dated'August 25, 1942; 2,371,752, dated- March` 20, 1945; and Patent No. 2,399,917, dated May 7, 1946 to Friden and Machado.

Referring to Figure 1, the machinel includes a body I5 inl which the actua-ting, selecting, and

control mechanisms are mounted, and carriage l5. which is mounted for endwise shifting movement transversely of body l5` and which carries numeral wheels il and i8 of the accumulator and revolutions counter', respectively, Carriage l5 can be shifted by power in either direction` by manipulation of respective shift keys I9, 2l).

Values are enteredV into the mach-ine by depression of numeral keys 2'2 of the usuall keyboard in the various ordinal rows thereof, keys 22 being releasable individually by depression of ordinal clear keys 22a, or collectively by depression of keyboard clear key 23. Values introduced into the machine may be registered addi-tively or subtractively on accumulator numeral Wheels I'l byV depression of plus key 25 or minus key' 2B, respectively. If desi-red, add key 28 may be depressedto cause clearing. of the keyboard in the usual manner after a single registration inthe accumulater.

Values registered in numeral wheels Il and It can be erased, i. e., the registers can be zeroized, by manipulation of respective manually operable resetting handles 29, 30 or by power through depression of return and clear key 3|.

The machine is adapted tov perform automatic plural order division by means of conventional construction including division starting controly lever 32. Automatic predetermined multiplication can also be performed by depression of multiplier selection keys 34 to set up the desired multiplier iigures as indicated on dials 3,5, and by depression of one of multiplication keys. 36,v 3l or 38 to start the multiplying operation. By depression of multiplier correction key 39 values entered into the dialsV 35 can be removed and the multiplier selection mechanism normalized.

Selecting and actuating mechanism Within casing l5, the frame includes left side plates 45 and 45a (Figure 4) and right side plate 4B (Figure 6) which are suitably mounted on base i3 and arev interconnected by various cross frame members including transverse brackets 4l, 48, 4,9 and 50 for supporting various mechanisms including the selecting and actuating mechanism.

The values to be introduced into accumulator numeral wheels ll are selected by means of a plurality of similar orders of selecting mechanism associated with numeral keys 22. For this purpose, each bank or order of keys 22 (Figure 2) cooperates with a pair of similar parallely springurged value selecting slides 54 mounted for end- Wise movement by a suitablel supporting linkage 3 and extending through suitable slots in cross frame plate 49.

Each selecting slide 54 (Figure 2) is connected at its rear end with a ten-tooth gear 58 slidably and non-rotatably mounted on longitudinal square shaft 51, whereby movement of slide 54 serves to position the associated gear 56 on shaft 51 with respect to stepped teeth of the associated actuating cylinder 58 in accordance with the value of the depressed numeral key 22. A pair of actuating cylinders 58 for adjacent orders of the machine are mounted on each longitudinal actuating shaft 6|, which is suitably journalled in cross plates 48 and 49 and has a suitable bevel gear connection with transverse shaft 62. Shaft 62 is operable cyclically in a single direction from clutch controlled driving means as described hereinafter to provide the only path of power flow from the motor.

Each shaft 51 (Figure 2) is suitably journalled in cross plates 41, 48 and 49, and between plates 41 and 48 has associated therewith selectively settable plus-minus gears for driving an aligned numeral wheel l1. The plus-minus gears of each order of the machine include a spool 1| slidably and non-rotatably mounted on shaft 51 and having opposed ten-tooth bevel gears 12, 13 arranged for selective engagement with gear 14 (Figure 3) on numeral wheel shaft 16. The engagement of gear 12 and 13 with gear 14 is controlled by strap 11 (Figure 2) which extends transversely of the machine between each set of plus-minus gears 12, 13 and is mounted by similar spaced arms 18 on transverse shaft 19, which is suitably journalled in side plates 45a and 46. Shaft 19 is controlled in a manner hereinafter described to determine positive registration by meshing gears 12 with gears 14, and negative registration by meshing gears 13 with gears 14. In the central neutral position shown in Figure 2, in which gears 12 and 13 may be held normally by suitable spring-urged centralizing means associated with strap 11, carriage shifting can be effected.

During additive and subtractive registration of values in numeral wheels I1, suitable transfer mechanism of conventional construction may be operative to effect the tens transfer as disclosed, for example, in said Patent 2,229,889.

Drive mechanism As stated above, the actuating means is operable cyclically to effect registration in the accumulator of the values set into the machine by depression of the numeral keys. For this purpose a clutch-controlled drive is provided for the actuating mechanism which preferably forms the sole drive means for all power driven parts of the machine. This source of power of the drive means comprises electric motor 8| (Figure 2) provided with drive shaft 82 carrying drive gear 83 (Figure 6) which is connected by idler gear 84 with gear 89 journalled on transverse shaft 62 and carrying driving clutch element or ratchet 81 on its hub. Driven clutch element 88 is secured on shaft 52 and has pivoted thereon spring- Iurged clutch pawl 89 having a tooth for engagement with the teeth of ratchet 81 to establish the drive connection. Pawl 89 is spring-urged to operative position but is restrained in the neutral or full cycle position of the parts by clutch control lever 9| pivoted at 92 on side plate 49. Lever 9| carries roller 93, which seats in a depression on clutch element 88 in the full cycle position thereof, and in other positions thereof maintains 4 lever 9| in its clutch engaging position for a purpose later referred to.

It is seen, therefore, that one or more cycles of operation of the actuating mechanism can be determined by oscillation of clutch control lever 9|.

Simultaneously with movement of control lever 9|, the circuit for motor 8| is established, and for this purpose pin 94 (Figure 6) on the upper arm of clutch control lever 9| is connected by link 95 with lever 96 pivoted at 91 on side plate 46 and connected at its lower end with lever 98 also pivoted on plate 46. Lever 98 has a suitable insulated pin 99 in overlapping relation with spring mounted conta-ct |00 normally spaced from similar contact |00. Thus, clockwise movement of clutch control lever 9| serves through link 95 and lever 96 to oscillate lever 98 in a counterclockwise direction whereby contacts |00 are engaged to establish the circuit for the motor. It will be noted that roller 93 in maintaining control lever 9| in clutch engaging position when thc actuating means is out of full cycle position also serves to maintain contacts |00 closed, so that the motor circuit can be interrupted only in the full cycle position of the parts.

Carriage shift mechanism Conventional means are provided to shift the carriage in either direction under control of the shift keys i9 and 20 such as disclosed in Eriden Patent No. 2,294,083. Carriage I6 (Figure 3) includes a frame |0| having a toothed shift rack |02 extending along the rear side thereof. The rack |02 .is adapted for engagement by shift pins |03 (Figure 2) on a shift gear |04 suitably journalled upon cross bracket 41. Shift gear |04 can be rotated selectively in either direction through suitable gear connections |05 to a. pair of similar gear sleeves |06, one of which is seen in Figure 2. Gear sleeves |06 are axially aligned with two adjacent actuating shafts 6|, and have similar engageable drive connections therewith. These drive connections are made by means of a clutch element or collar |01 having a slidable drive connection with one of the actuating shafts 6| and shiftable by means of a fork |08 carried by a shift rod |09. Rod |09 is slidably mounted in cross brackets 48 and 49 and is spring urged by a spring |'|0 to the inactive position shown in Figure 2. There are two shiftable rods |09 which are selectively moved to active position by a suitable means from the respective shift keys I9 and 20.

Multiplier mechanism The multiplier mechanism comprises a ten key keyboard including keys 34 (Figures 1 and 4) and a pin carriage |2| (Figure 4) associated therewith, having ten ordinal rows of settable stop pins |22 and ten ordinal differentially adjustable elements |23 (Figures 4 and 8). Adjustable elements |23 are in the form of spring-urged racks into which the digits of the multiplier may be set successively for subsequent control of the multiplying operation. Each rack |23 is normally held inactive by a latch lever |24. In order to set up the multiplier digits, each pin row includes eight pins corresponding to the 1 to 8 keys and a fixed stop |35 corresponding to the 9 key so that a depressed multiplier key operates through a conventional lever system as disclosed in Patent 2,371,752 to set the corresponding pin of an aligned ordinal row to active or raised, position. At the same time that a pin 't5 of the pin carriage .fis Amoved to active posit-ion, the alignedvra'ckiis :released vfrom :its `vlatch :|24 to :move into `engagement Ywith -the 'active pin |22 fand thereby be set differentially `in accordance with the values of the depressed .multiplier key. .The vdepressed multiplie@1 'key alsooperates a .conventional .form :of escapem'ent mechanism .to

.move thepin .carriage one .ordinalfstep Iwith `respect to the multiplier -selectiommechanisxn As shown in Figure =1,-.the `carriage |2| yhas -been moved live steps :from tits normal position by -de- .pression of :the-zerorkey 234. This Vmechanism is of l,thetype :disclosed in said Patent 2,311,752.

The fdifferentially adjusted Vpositions yofl each rack |23 fis lutilized ein -a well knowny manner .to control-the .--number -of registrations in a corresponding t ordinal position l.-of the accumulator, fto shift .thevlaccumulator from lett tto right following multiplication =byeach=multiplier -digit,.t.0-en able correct Vregistration of fthe neXt -ordinal product, as Well as to fshift the pin carriage one step so ythat thenext higher :order rack |23 'comes into controlling position with respect to the-operation of the machine. To enable exercise of the above controLa conventional pawl drive (not shown) -is .provided -for returning veach-adjusted rack step by step :to .its initial position, Tthis operation being successive `from the adjusted rack of lowest order krwiththe shifting of the accumulator 4and the multiplier pin `A`carriage following the last ystepfof movement of `each Vrack to condition the Ymachine vfor Voperation 'in the next higher order. As the pinv carriage `.is returned step-by-step-ftowardthe right as viewed in Figure 1, .pin Arestoring -ngers |f25 `of conventional `conf struction which engage the 'slotted lower ends vof pins |22 act to Yrestore the active pins fof the respective rows 'to inactive position successively.

i-As explained vin said -Patent 2;399,917, when one `of ythe vkeys 36, 31 or 38 is depressed rand latched into depressed position, the multiplying operation is performed by rst returning thefcarriage Vto its end position (with :resetting of the register if the key 38 Vis depressed). After the carriage-is `in its end position, the multiplying operation proceeds Ain the usual fashion under control lof the adjusted racks of the multiplier carriage |2-|.

As -seen in Figures 4 and 8, ythe :multipliercark riage |2I comprises end plates |26 which may 'fbe connectedby'suitabletie rods |21. Adjacent its lowerportion, the carriage |21 isslidablyfengaged and supported by a `transverse :rod 28, 'while rat its upper-end'vthe carriage has a roller :|29 .anda rack I3-I engaging .a :guide |32 on fthe frame "of the machine. rllhe escapement mechanism for determining 'step-by-istep shifting movement of the multiplier carriage vto the left as `viewed 'in Figure during'the setting ofthe values 'intofthe multiplier unit is of conventional .construction and includ-es the :rack |3-IV and the spring-.urged lever A|11-Z3-(ll,igure4) having an .upstanding portion engaging 4an .end plate |26 'of the carriage.

The power 'return of fthe carriage in Ystep-bystep -f-.ashionds provided for by-means vof rack-L36 (Figures -4 and `8) :which Ais fadapted for engagement by the tooth |131 `of shift `pawl f|38 which is normally :positioned below the rack |36 asseen in IFigure-4. The pawl I38is journalledzabout a suitable-eccentric f|4 I 'carried :bycollar f|i42 which is.s1idable onshaft 439. Shaft '|39 :has afsuitable drive connection with the transverse shaft162. Pawl |38 is also slotted to engage a stationary guide pin |43. Collar |42 is provided with a groove Yengaged by pin |44 carried 'by an ada6 ajustable .contrclfarm 146 having-.clutch teeth 141 ,associated with similar rteeth M8 yon ithe v.control 'shaft-|149 'Ihe clutch connection 141 .-|48-;pro `vides for rocking :adjustment of v`control arm-f|46 .b y .clockwise fmovernent of itheshaft i 49 -or independently of --shait |119. During -the 4.multiplying operation the shift gpawl f| 38 is frais'ed at the :end of each :ordinal multiplyingfoperationby roc-king iof shaft :|49 fito cause a A.one -step :shift yof-fthe multiplier-carriageso.that theracks 23 `are successively restored to aero.

Aseseenfin Figure -.4, each rack f|f23 is urged fin ajclockwise direction by aspring |5I. fFigure shows thej-postion @of `the rack f|23 'when .set to the valueof 9. In vthe 9 positionrof "a rack |f23ta Eportionpf the rack :engages -a cross rod |56 Ac-arried lloyza jlever member vI 5-1 which i-s `ipivoted at |58 -on the carriage 12|v and is islotte'dto engage pivot rod A|59 of the racks |--23. The iengagement of one end of the slotwith `the yrod 459 under Athe Ainfluence y'of lspring r-I 61| Vprovides a normal position-of -thearm |51and xthe rod |56. As Vwill .be later described, the -ro'd fl56provdes means for restoringanyfadjusted rack 4723 to Zero position yafter :the shifting .of the pin foarriage to --its inactive position.

In order `to Acorrect .the multiplier setting, -the correction -key 39 -.is depressed. The 'depression of Athis vkeyserves to enable -the :power shift for returning .the multiplier for pin=carriage and also to enable the shift Y'for the accumulator fcarriage to return it to its rend position. Key 39 `(Figures 2 and 4) -is spring-'urged=|;o the raised position show-nfand .is adapted .to be ilatched fin depressed position by engagement rof spring-urged latch arm1|66 withran-.extension .|r61 `ofl thelkey. fAdacent its'lower end Ykey -39 Ihas 1.a y,pivotal pin and slot-,connectonratI-.SS (Figure l2) witha lever|69 pivoted on van auxiliary frameplate |10 at l|11|. The lower arm of lever.|69 carries afpin f|:1-2 aengaged z-inA a slotted link ,|13 `.which also `engages a pin |14 on arm |46. Spring |.1.6 isfconnected between pin |14' and a suitable stud |11 on the frame of the machine to 'urge the parts to the position -shown -in :Figure 2. Spring |16 :also serves through farm `|46to maintain pawl |38 below `rack :|:361as vshown in 4. v"Upon depression of1keyf39,f1ev-er |69 (Figure'Z) .isjro'cked in a'a'counterclockwise direction torockfarm |46 in a clockwise direction, and vto `vraise the actuatingspawl 198 Y(rFigure'li) for the pin carriage return rshift. The tpincarriage will therefore be returneclone' step'with each cycle of the machine and'rwifll be restored 'Ito fits initial position, which r is -one cycle mOrethan the :number of :set multiplierracks |23. Depression of key39 `(Figure 2) also :operates .throu'ghroll'er |'8| on lever |169 Ato oscillatefan farm 1:82 'carriedby transverse shaft |8-3 rwhich also (Eigure '6) `carries anupstanding arm +84 with xits upper forked fend embracing a pin |86 zcarried by fslid'e'ill mounted 'Ifor fendwise sliding :movement on the -frame lof the machine. lThe fendof 4slide 81 4kabuts pin j91| carried by clutch Ycontrol lever 9|, so that .movement lo'f slide '|81 =to the right, zas 'viewedin Figure 6, not only 'engages the' clutch, :but lalso 'operates through the link 95 and levers 96 and 98 =to close `'the v'contacts zI 00.

During the last 'cycle of shiftingvmovement, 'the lever |51 (Figure 4) has'its arm 1|9| moved into operative relation with cam |92 to be-oscillated thereby yin ia 'fcounterclockwise direction during such .last cyclesoithatrod |56 'will restore racks |.2-3 ltoitheir zero positions. Cam |92 is .suitably driven .in fcyclic fashion :from .the isha'ft162.

Preferably also the key 39 engages the carriage shift to return the accumulator carriage to its leftmost position to facilitate the multiplying operation. Such a multiplying operation starts With a return of the carriage to its leftmost position and is shortened if the return is effected simultaneously with the multiplier correction operation. For this purpose roller |8| (Figure 2) is operatively engaged with an arm 20| secured on a shaft 202 which also carries an upstanding arm 203. At its upper end, arm 203 carries a pusher arm 206 operatively related with a pin 201, carried by depending arm 208 on a shaft 209. Arms 203 and 20E are connected by spring 204. Shaft 209 also carries depending arm 2|| which is operatively engaged with the end of shift rod |09 which controls shifting to the left. Spring for shift rod |09 is stronger than spring 204 so the parts are normally positioned as shown in Figure 2.

As explained in said Patent No. 2,399,917, when the accumulator carriage shift mechanism reaches an end position, it overdrives one cycle, and this cycle is ordinarily utilized in a multiplying operation to trip the multiplying mechanism for operation, and when the carriage shift is enabled by depression of key 39, this trip for the multiplying operation must be disabled. As seen in Figure 2, the lever |69 has an oiset portion 2|2 operatively related to an upstanding finger 2|3 pivoted on shaft 2|4. Finger 2|3 is connected by cross piece 2| 5 (Figures 2 and 7) to a locking finger 2 6 (Figure '1). Upon depression of key 39, iinger 2|6 is moved beneath pin 2|1 of a multiplier control arm 2|8. Arm 2|8 is normally held inactive by latch 2|9 which is tripped during the overthrow cycle of the shift to start the multiplying operation. However, with the correction key 39 depressed, locking nose 2 I6 moves beneath pin 2 |1 to hold the arm 2|8 inactive and thereby prevent the initiation of a multiplying operation.

Operation,

In operation, when an erroneous multiplier iigure is set into the dials 35, the operator depresses the correction key 39. Key 39 (Figure 2) through lever |69, arm |82, shaft |83 and arm |84 (Figure 6) operates to engage the clutch and enable the motor circuit, and, through lever |69 (Figure 2) link |13 and arm |46 enables shift pawl |31 (Figure 4) to eiTect step-by-step return of the pin carriage |2 As each rack |23 is withdrawn from view its active stop pin |22 is Withdrawn by the associated linger |25 and the rack moves to its nine position against pin |56 as seen in Figure 5. During the overthrow step of carriage |2| when finger 9| is moved into alignment with cam |92, cam |92 becomes operative to restore all displaced racks |23 to their zero position Where they are held by latch levers |24. Also during this overstroke cycle, lever |33 operates in a manner disclosed in the above-mentioned Patent Number 2,371,752, to move latch arm |66 to inactive position so that key 39 is restored to raised position by the spring associated therewith.

During the time key 39 is depressed, the accumulator carriage I6 is also moved step-by-step toward its left end position.

We claim:

1. In a calculating machine having a multiplier selection mechanism including a carriage provided with a plurality of orders of differentially settable elements spring-urged toward the 8 nine position, a latch for each of said elements normally holding the element in zero position, eight selectively settable pins for each element operable to stop the element in the one to eight positions when said latch is released, a means common to all said elements to stop each element in the nine position, said carriage being displaceable step-by-step from an initial position during successive setting of said elements, means for returning said carriage beyond said initial position to a restoring position, means for withdrawing stop pins which have been set upon movement of said carriage to said restoring posi- 4tion thereby permitting the associated elements to move to the nine position determined by said common stop means, means operable upon arrival of said carriage in said restoring position for moving said common stop means to restore all elements in the nine position to the zero position for latching by said latches, and means operable after the setting operation to initiate operation of said carriage returning means and said common stop moving means.

2. In a calculating machine adapted to perform multiplication calculations, a multiplier selection mechanism including a carriage provided with a plurality of orders of differentially settable elements, a keyboard comprising ten keys for entering the multiplier value in said selection mechanism, selective depression of one of said keys causing differential setting of one of said elements followed by movement of said carriage into the next ordinal position, said carriage being moved step-by-step from its initial position as the multiplier value is entered into said selection mechanism., means for normalizing said selection mechanism including a manually operable control key, means for shifting said multiplier carriage to its initial position, a cyclioally-operable power drive means for actuating said shifting means, means responsive to operation of said control key for causing said drive means to actuate said shifting means to return said carriage to initial position step-by-step during successive cycles of said drive means, means for restoring said differentially-settable elements to Zero position, and means driven by said cyclically-operable drive means operative upon arrival of said carriage in initial position to actuate said restoring means.

3. In a calculating machine having a frame, a selection mechanism including a carriage having a series of pivotally mounted axially aligned differentially settable elements, said carriage being displaceable relative to said frame step-bystep from an initial setting position during successive differential setting of said elements, mechanism for restoring said selection mechanism comprising a restoring member mounted on said carriage for movement therewith and operable to restore any of said elements from a common setting to zero setting, a cyclically operable cam rotatably mounted in said frame, means for returning said carriage beyond said initial setting position to a restoring position, means operable during return of said carriage for positioning differentially set elements in said common position, said cam operating said restoring member upon arrival of said carriage in the restoring position, and means operable after the differential setting of said elements for initiating operation of said carriage returning means and said cam.

4. In a calculating machine adapted to perform multiplication calculations, a multiplier selection mechanism including a carriage provided with a plurality of orders of differentiallysettable elements, a keyboard comprising ten keys for entering t-he multiplier value in said selection mechanism, selective depression of one of said keysl causing differential setting of one of said elements followed by movement of said carriage into the next ordinal position, said carriage being moved step-by-step from its initial position as the multiplier Value is entered into said selection mechanism, cyclically operable means for shifting said multiplier carriage stepby-step, toward its initial position, adjustable control means for rendering said shifting means effective, a cyclically-operable power drive means for actuating said shifting means, an operation key, means actuated by depression of said operation key for initiating operation of said drive means and for adjusting said, control means to thereby effect substantially uniform cyclic operation of said shifting means simultaneously with operation of said power drive means to return said carriage one step for each successive cycle of said drive means while said key actuated means is in actuated position.

5. In a calculating machine adapted to perform multiplication calculations, a multiplier selection mechanism including a carriage provided with a plurality of orders of differentiallysettable elements, a keyboard comprising ten keys `for entering the multiplier value in said selection mechanism, selective depression of one of said keys causing differential setting of one of said elements followed by movement of said carriage in-to the next ordinal position, said carriage being moved step-by-step from its initial position as the multiplier value is entered into said selection mechanism, means for returning said carriage toward said initial position comprising a rack on said carriage and a cyclic shifting element engageable therewith, a power drive means for said element including a cyclic clutch for controlling operation thereof, said element being normally disposed in a position where it is inoperative upon said rack, control means for moving said element into operative position with respect to said rack, an operation key, means actuated by said operation key upon depression thereof for engaging said clutch, and operating connections between said key and said control means responsive to depression of said key for moving said element into said operative position to maintain said carriage returning means cyclically operable in time with cyclic operation of said clutch, to thereby effect returning of said carriage one step for each cycle of said carriage returning means and said clutch.

6. In a calculating machine adapted to per- 10 form multiplication calculations, a multiplier selection mechanism including a carriage provided with a plurality of orders of differentiallysettable elements, a keyboard comprising ten keys for entering the multiplier value in said selection mechanism, selective depression of one of said keys causing differential setting of one of said elements followed by movement of said carriage into the next ordinal position, said carriage being moved step-by-step from its initial position as the multiplier value is entered into said selection mechanism, an `accumulator rfor registering a product mounted in a shiftable carriage, means for shifting said accumulator carriage toward its left end position preparatory to registering of a product in said accumulator, means for shifting said multiplier carriage to its initial position, a cyclically-operable power drive means for actuating both said shifting means, correction means responsive to shifting of said multiplier carriage to its initial position for effecting restoration of previously set diiferentially-settable elements to normal positions, an loperation key, means actuated by depression of said key for effecting operation of said multiplier carriage shifting means by said power drive means to shift said multiplier carriage to its initial position, and means also actuated by depression of said key for effecting operation of said accumulator carriage shifting means by said power drive means to shift said accumulator carriage toward the left, whereby while said multiplier carriage is being shifted toward its initial position preparatory to the entering of a new value in said selection mechanism, said accumulator carriage will be shifted toward its left end position preparatory to registering of a product in said accumulator.

CARL M. FRIDEN. ANTHONY B. MACHADO.

REFERENCES CITED The following references are of record in the file of this patent:

UNITED STATES PATENTS Number Name Date 765,774 Goldberg July 26, 1904 1,787,489 Muller Jan. 6, 1931 2,019,900 Fuller Nov. 5, 1935 2,074,017 Fuller et al Mar. 16, 1937 2,263,479 Williams Nov. 18, 1941 2,371,752 Friden Mar. 20, 1945 FOREIGN PATENTS Number Country Date 546,457 Gennany Mar. 14, 1932 

